Part of: Mac storage full? Find what is using it and free up space safely (Storage full)
Your Library folder holds the data apps keep for you: settings, caches, saved state and downloaded content. It is normal for it to be large. It is not normal to delete it, and you should not try. The useful question is what inside it is big, and whether you can recognise it.
What the Library is
There are two Library folders. The one in your home folder, ~/Library, belongs to you and your apps. The one at the top of the disk belongs to the system and should be left alone. This article is about the first.
Finder hides ~/Library by default. In Terminal you can read it directly.
See what is big inside it
These commands only read. Run them in Terminal:
du -sh ~/Library
du -h -d 1 ~/Library | sort -hThe first prints the total. The second prints each subfolder, with the biggest last. On a Mac in regular use you will usually see Application Support, Caches, Containers and sometimes Developer near the end. It can take a minute.
The usual large folders
- Application Support. Data apps need to work: databases, downloaded content, settings. Often the largest of all.
- Caches. Temporary copies apps can rebuild. See what is safe to delete in Library Caches.
- Containers. Data of sandboxed apps. It belongs to the app, and it is not a cache.
- Mail and Messages. Attachments and mailboxes. See Mail and Messages.
- Developer. Xcode data, simulators and build products. See how to clean up Xcode.
Terminal may not be allowed to read some of these folders. If a folder shows a smaller size than you expect, or an error, that may be why.
Safe, Risky, Never
- Safe: caches of apps you know, once you accept that they rebuild and the app may be slower the first time. Leftovers of an app you deleted and are sure you will not reinstall.
- Risky: anything in Application Support, Containers and Mail. It may hold data that exists nowhere else, such as saved documents, databases and offline content.
- Never: the Library folder itself, folders you cannot name, and anything in the system Library.
What breaks if you get it wrong: an app can lose its settings, accounts, saved data or offline content, or refuse to open until reinstalled. Deleted files may not be recoverable.
Leftovers from deleted apps
When you drag an app to the Trash, the data it saved in Library usually stays. If you are sure you will not use the app again, those folders are leftovers. Read app leftovers on a Mac first, because some apps share folders with others.
A careful way to work
- Find the biggest subfolder with the commands above.
- Go one level deeper in that folder.
- Identify what it belongs to. The folder name usually names the app.
- Decide with the box above in mind.
- Move it to the Trash rather than deleting it permanently, and use the app for a few days before you empty the Trash. See why the Trash does not free space until you empty it.
Why Library keeps growing
Library grows because apps write to it and rarely clean up after themselves. A browser stores pages and images. A chat app stores conversations and files. A creative app stores previews and scratch data. Each does its own small job, and the total only becomes visible when you add it up.
Apps you deleted long ago can still own folders here. If you try many apps, the leftovers pile up. That is why a folder in Library that looks unfamiliar is often not a mystery, just an app you no longer have. Check the name before you decide. When the name does not help, leave the folder alone and look at its size: a small folder is not worth the risk, and a large one is worth a little more research.
See it by category
DiskJoy is our product. It scans the folders you allow, including parts of Library, and shows what it found with a plain explanation for each item. A scan only reads file sizes and dates and changes nothing. DiskJoy is pre-alpha and cleanup is not available yet, so you remove things yourself. Download DiskJoy for Mac to try a scan.
Next step
Back to the complete guide to freeing up space on a Mac, or read what is taking up space on my Mac? for the wider view.
Frequently asked questions
Why is my Library folder so big?
Library holds data apps keep for you: caches, support files, saved state and downloaded content. Over the years, many apps add to it and few remove anything.
Can I delete the Library folder on a Mac?
No. It holds your settings and app data, and removing it would make apps lose their data. Only look inside it for specific, recognisable items.
How do I see the size of the Library folder?
In Terminal, du -sh ~/Library prints its total. du -h -d 1 ~/Library | sort -h shows its largest subfolders.